1. Field of the Invention
The present invention relates to power supply technology and more specifically, to a power supply device having zero switching voltage.
2. Description of the Related Art
FIG. 1 is a circuit block diagram of a conventional dual forward converter type power supply device. According to this design, the power supply device comprises a first switch 100 and a second switch 110 at its input side, and a power output unit 130 at its output side. The power output unit 130 provides a Vout voltage output.
According to the aforesaid dual forward converter type power supply device, when the first switch 100 and the second switch 110 are switched on, a voltage drop is produced at the parasitic body diode. Therefore, it is necessary to overcome switching loss caused by such a voltage drop during a switching operation. Overcoming this switching loss results in lowering of the power supply efficiency of the dual forward converter type power supply device.
Therefore, it is desirable to provide a power supply device having zero-switching voltage that eliminates the aforesaid problem.